Research on Contamination of Foods with Mercury Mining: A Ten-Year (2011-2020) Bibliometric Analysis

The first study on bibliometric network analysis of research on contamination of foods with mercury (Hg) mining is presented. The Hg mining has been reported as the primary source of toxic Hg contamination of foods. The living population’s exposure to Hg is highly associated with the consumption of Hg-contaminated foods and water. This study aims to explore the global scientific literature to gain insight into how the scientific literature addresses contamination of foods with Hg mining using bibliometric network analysis. The study was conducted on 319 documents from publications indexed in the Scopus database from 2011 to 2020. We collected reviewed documents using various techniques to analyze this issue, including general statistics, bibliometrics, and analytics. According to analysis results, several significant findings were found as follows. The co-authorship network demonstrates the relationship among authors and countries regarding contamination of foods with Hg mining. Co-authorship authors and country analysis indicate that “Chinese authors” and “the Chinese Academic of Sciences” are the first among the most influential authors and institution, respectively. Moreover, from systematic visualization of co-occurrence keywords and clustering analyses, six major clusters were reviewed and have been identified as potential opportunities for future research.

Biochar as a Soil Amendment: Reduction in Mercury Transport from Hydraulic Mine Debris

Mercury mining and its use in gold mine operations left a legacy of contamination in northern California. Contaminated sediments and water continue to affect local and downstream ecosystems. To assess the efficacy of biochar-amended soils on decreasing Hg transport, biochar was used to amend rock and sediment columns and mesocosms to decrease suspended sediment and associated mercury (Hg) in storm water runoff from Sierra Nevada hydraulic mines. Mercury-contaminated storm water runoff and hydraulic mine debris were collected from two hydraulic mine sites in the Yuba River, California watershed. Mercury concentrations and turbidity were analyzed from storm water samples and hydraulic mine debris in three simulated storm runoff experiments using decomposed granite columns, sediment columns, and sediment mesocosms amended at 0%, 2%, or 5% biochar by weight. Columns containing hydraulic mine debris and mixed with 5% biochar had a significant (p < 0.05) reduction in filter-passed mercury (FHg) in the outflow as compared to control columns. To simulate saturated hydraulic mine debris runoff, mesocosms were filled with mine sediment and saturated with deionized water to generate runoff. Five percent biochar in mesocosm trays decreased FHg significantly (p < 0.001), but, because of the angle of the tray, sediment also moved out of the trays. Biochar was effective at reducing FHg from hydraulic mine discharge. Biochar in laboratory columns with decomposed granite or mine sediments was more effective at removing Hg than mesocosms.

Toxic Meals for Seabirds and Seals: Monitoring Mercury in the San Francisco Bay

Mercury is a metal pollutant that travels thousands of miles through air and water. It flows along rivers to lakes, estuaries, and the sea, cycling between animals and their environments. Extensive mercury mining during the Gold Rush left lasting impacts on the San Francisco Bay Delta, one of California’s largest wetland habitats and home to thousands of species. Burning fossil fuels in cities like San Francisco also releases mercury, leading to its buildup in local food chains. Mercury accumulates from plankton to fish to top predators like sharks and seals, where it reaches potentially harmful levels. Mercury never fully breaks down and continues cycling in ecosystems, even reaching migratory animals living offshore in the Pacific Ocean. Scientists collect samples from wildlife to uncover clues about mercury sources and threats to human health. This article explains the mercury problem and why we track this invisible pollutant in the San Francisco Bay.